As indicated at the outset, enumerative studies of the crimes committed by apprehended marihuana, law violators and non-drug offenders identified as marihuana users cannot, by their very nature, either prove or disprove a causal connection between the use of cannabis and the commission of crimes; nor can their rates of crime be projected onto the larger universe of marihuana users.

As several researchers have pointed out, those individuals apprehended for marihuana offenses represent only a. tiny fraction of all marihuana users (Kaplan, 1971; Weitzner, et al., 1971) ; likewise, those in other offender samples who are identified as marihuana users represent only a small proportion of the offender populations of which they are a part (Bromberg, 1939; Bromberg and Rodgers, 1946; Kaplan, 1971).

Although the data do indicate that some individuals identified as marihuana users are subsequently involved in crime, both drug-specific and non-drug offenses, they do not provide support for the thesis that cannabis was the determining factor in their criminal careers. Likewise, they fail to indicate that the rate of progression to other crimes manifested by these offenders was significantly greater than that which might be expected in either a non-using criminal subgroup or the general population.

As Tinklenberg (1971) has stated:

The important issue is that unless one has systematic data on the proclivities toward crime of the various subgroups of marihuana users, one cannot answer the crucial question of whether the use of marihuana alters the actual rate of crime among these various subgroups over the criminality which would be expected. At this time, it is unknown whether individuals with these characteristics seek the use of marihuana or whether the use of marihuana in any way contributes to the development of these traits (P. 24).

By reading between the lines of these enumerative studies, however, one would be tempted to postulate that individuals with certain psychological, social and cultural characteristics are more likely to seek the use of marihuana, than is marihuana likely to contribute to the development of delinquent or criminal behavior patterns.

The number of researchers pointing to individuals with long histories of psychological maladjustment or disturbances has already been noted. Others have alluded to persons involved, prior to cannabis use, in criminal or delinquent subcultures (Blumer, 1967; Robins, et al., 1970; Kaplan, 1971; Weitzner, et al., 1971). Still others suggest that marihuana use is more likely to develop among persons living in underprivileged communities or within a social structure that limits achievement and advancement (Asuni, 1964; Blumer, 1967; Goode, 1972).

In recent years, considerable evidence has been gathered to suggest that the use of other drugs and association with drug-using friends are also likely to enhance the probability of marihuana use (Hochman and Brill, 1971; Goode, 1972; Abelson, et al., 1972).

Because many of these characteristics are likely' to be associated with both criminal or delinquent behavior and marihuana, use, some individuals have mistakenly concluded a. cause-effect relationship rather than a statistical correlation.

The studies reviewed in the following pages axe probably the most methodologically adequate assessments of the. purported relationship between marihuana and crime undertaken to date. The data show that the seemingly significant statistical correlation often observed between marihuana, use and crime is spurious; it is dependent not on the chemical effects of the drug but upon the operation of several extra-pharmacological variables which have little or nothing to do with the use of marihuana. per se.

The first of these studies (Goode, 1970) is based on a sample of marihuana users. Because it, like the study by Robins and his colleagues (1967, 1970) referred to earlier, involves a selected population, the extent to which its findings can be applied to the general population remains speculative.

The second study presented, a Commission sponsored survey of young male urban dwellers, is probably the most adequate assessment to date of the relationship between marihuana use and crime. The results are based on a representative sample of the general population of males, 15 to 34 years of age, the self reports of criminal behavior have been cross-checked with Philadelphia Police Department files; and numerous statistical controls have been applied to the data. The study therefore provides at least tentative answers to the following questions:

-Do young, male marihuana users and nonusers in the general population differ significantly in the nature and extent of their criminal activities?

-Is marihuana use, in and of itself, the principal determinant of any observed differences? -If not, what are the variables which explain a statistical correlation between marihuana use and crime?

Goode, 1970. Between February and September of 1967, face-to-face interviews were held with 204 marihuana users residing in the New York City Metropolitan Area. The sample, admittedly nonrepresentative, was drawn front membership lists of drug-related organizations and also included friends and acquaintances of the researcher.

The sample, suspected of differing to some unknown extent from a random sample of marihuana users, can be characterized -as primarily male (53%), young (median age 22 years), white (89.5%), single (78%), middle class urban dwellers, including students, dropouts, business people, housewives and the unemployed (p. 316).

All of the respondents, by virtue of their marihuana use, possession or sale, had engaged in law violative behavior, but, only nine marihuana arrests were reported. This finding indicates that persons who are arrested for marihuana related activities constitute only a small fraction of total marihuana users.

Because of their marihuana-related criminal activity, one would expect that persons in this sample would have a higher probability of being arrested than would the "average" person from the general population. To determine if, in fact, this might be the case, the researcher computed the rate of arrest for his sample and compared it with the national rate of arrest provided by the Federal Bureau of Investigation for the year 1965. Despite the fact that the rates are not strictly comparable (the sample rate is based on arrests ever experienced; the national rate is based on the number of arrests recorded for one year), the similarity is striking. The national rate was given as 3.7 per 100; the sample rate was computed to be 3.9 per 100 per year, 4.5 if one adds the marihuana arrests (p. 236).

Although the arrest, rates of the users and the general population were found to be roughly similar, the types of crimes committed by the users differed significantly from those crimes recorded for the population as a whole. In contrast to the majority of drunkenness and disorderly conduct charges noted for the general population, the offenses of the users most often resulting in arrest involved participation in political demonstrations (19 out of the 55 arrests). No other single offense attracted more, than a few arrests (p. 2335).

In addition to examining arrest rates and the types of offenses committed, the researcher also investigated the relationship between the amount of marihuana smoked and the criminal behavior of the user. If it were true that marihuana did produce a dangerous and criminogenic state in the user, the greater would be his likelihood of committing crimes and of being arrested.

The data, however, show no relationship; excluding the "political crimes" (which were most common among the least frequent smokers and least common among the most frequent smokers), the "serious" crimes committed by 15 respondents (non-marihuana narcotics possession, disorderly conduct, drunkenness, burglary, theft, assault, auto theft, serving liquor to a minor and larceny) resulted in a total of 21 arrests. The heavy smokers did not commit these crimes significantly more frequently than did the light smokers.

Similarly, there was no relationship found between the frequency of use and the likelihood of arrest; three of the daily smokers, three of those who smoked three to six times per week, three who smoked one or two times weekly, one who smoked four times monthly and three who were less than monthly smokers were arrested for committing these "serious" crimes (pp. 237-38).

The researcher concludes that:

Although these numbers are extremely small, the fact of their perfect dispersal is perhaps indicative of the lack of a crime-inducing effect of the drug. It is, at any rate, a proposition which ought to be tested more systematically in the future with more complete data. For the moment, there are indications that point to the fact that the marijuana smoker is no more criminal than the rest of the population (p. 238).

Goode, 1972. The Commission-sponsored Philadelphia survey set out to resolve these issues. Goode (1972) analyzed the data collected during August of 1971 from an interview survey of 559 15-to-34-year-old residents of West Philadelphia.

That part of the report devoted specifically to the analysis of the data is presented in its entirety below. The only deletions made were the author' references to previous studies bearing on the issues addressed, the findings of which have been presented earlier in this chapter.